This invention relates to a containment system and, more particularly, to a means for and method of installing membranes in containment pits for casingheads of oil wells or tanks storing liquids and semi-liquids which are hazardous to the environment. It is known to line cavities in the earth with fluid impermeable sheathing, and particularly, for lining storage tanks or the like. These known coverings are sheets of a flexible and fluid impermeable material. These liners or sheets are usually sealed one to another.
However, these known fluid impermeable sheathings have various drawbacks.
One of these drawbacks is that the lining collapses when the cave is emptied of fluids. Such a collapse often impedes any further utility of the cavity as a container.
Another disadvantage is that is difficult to avoid complete bonding of the sheathing to the cave surface and in this way, avoiding ruptures in the sheathing if there are fissures in the wall of the cavity.
One known solution for these disadvantages is to support the sheathing on a frame.
This solves the stated disadvantages, but other disadvantages are introduced including:
(1) reduction in the cave's capacity, due to the presence of the frame;
(2) an unsatisfortory service-life of the supporting frame, because of corrosion taking place when the frame comes into contact with the fluid that is enclosed in the cave or other cavity serving as a container which requires periodic upkeep and servicing of the frame;
(3) the possibility of contamination of the fluid;
(4) the difficulty in mounting the supporting structure for the sheathing; and
(5) the high cost involved for lining a cave or other cavity.
Certain other drawbacks are directed expressly to casingheads of oil wells. How to get the membrane to form a seal around the shaft of the casinghead? How to get the membrane around an established casinghead and still have a membrane that is properly sealed against fluids? How to get the membrane around an existing storage tank and still have a membrane that is properly sealed against fluids?
An object of the present invention is to provide a fluid impermeable membrane for lining cavities in the ground. Another object of the present invention is to provide a fluid impermeable membrane that is adaptable to all types of casingheads for all types of wells, i.e. oil wells, gas wells, injection wells and disposal wells. Still another object of the present invention is to provide a fluid impermeable membrane that is capable of being adaptable to all types of existing storage tanks or the like.
Other objects will become apparent from the following description with reference to the accompanying drawings wherein: